The present invention relates to a method and instruments for installation of a patellar button prosthesis. In the prior art, it is known to resect the patella for the purpose of installation of a patellar button prosthesis. Heretofore, no system of instruments has been developed which enables the surgeon to accurately take into account all parameters of surgery which must be taken into account in order to perform the surgery in a satisfactory matter. Such aspects of surgery as ensuring that adequate bone stock will remain after resection and that holes drilled in the patella will not be unduly deep in light of the amount of remaining bone stock have not to this time been taken into account in the design of instruments for performing such surgery. Further, to this time, instruments have not been provided for this type of surgery which are flexible enough to be utilized in a satisfactory manner for patellar buttons of different sizes and configurations.
The following prior art is known to Applicant:
The following prior art references are believed to be of general interest concerning the inventive saw guide:
U.S. Pat. No. 966,500 to Wegner discloses a combined holder and centering tool which is best seen in FIG. 1 to include a pliers-like device including jaws 5 and 6 and further including a centering tool 8 pivotally mounted on a common axis with the axis of rotation of the jaws 5 and 6 and having an end 9 with a centering hole 10 therein which is provided to center a boring tool. While some general analogy may be drawn between the centering tool 8, 9, 10 of Wegner and the drill guide of the present invention, it must be noted that the centering tool of Wegner is extremely limited in that it may only center the boring tool along an arc defined by the length of the portion 8 and the axis of rotation thereof. In contradistinction to this, the drill guide of the present invention may be located anywhere along the saw guide jaws where desired and thus provides infinite adjustability of the location of the centering holes thereof. This patent is believed to be only generally relevant as showing the combination of a pliers-like instrument and a drill guide.
U.S. Pat. No. 3,035,581 to Bonta discloses a power driven surgical knife having a guide bar laterally spaced from the blade for aiding in determining the thickness of the cut. This is believed to differ from the inventive saw guide in that as explained hereinafter, the surgeon cuts the patella along a plane defined by one side of the jaws of the saw guide which jaws remain stationary during the cut. In Bonta, the guide thereof moves with the blade thereby causing instability during the resection process.
U.S. Pat. No. 4,457,307 to Stillwell discloses a bone cutting device for total knee replacement which includes an assembly for mounting to the femur which has pivotally and longitudinally attached thereto a carriage carrying a power saw. The power saw disclosed in Stillwell may if desired, be usable with the present invention and if so used, the power saw blade would be aligned with the posterior edge of the jaws of the saw guide of the present invention. The details of the device disclosed by Stillwell are accordingly only believed to be of general interest concerning the teachings of the present invention.
Regarding the inventive drill guide, the following references are believed to be generally related thereto:
U.S. Pat. Nos. 2,181,746 and 2,291,413, both to Siebrandt disclose combination bone clamps and adjustable drill guides. These devices are believed to be of only general interest concerning the present invention in that the drill guides of the Siebrandt patents are oriented substantially perpendicular to the orientation of the drill guides of the present invention. The Siebrandt drill guides rely upon holes formed in one of the jaw members of the related bone clamp for their operation whereas in the present invention, the only holes are formed in the drill guide itself which is slidably mountable on one of the jaws and includes a drill guide portion which protrudes over the opening formed by the inner surfaces of the jaws when closed about the patella.
U.S. Pat. No. 3,804,546 to Boyajian discloses a drill guide including adjustability thereof enabling pivoting and rotation thereof with respect to its handle. There is no means disclosed in Boyajian to attach the drill guide to a jaw of an associated saw guide, and as such, this patent is believed to be of only general interest.
U.S. Pat. No. 3,835,849 to McGuire discloses a bone clamp and adjustable drill guide wherein a bone may be clamped between on the one hand a member 1,5,6,7 and another member designated by reference numeral 13. The member 13 also includes holes therein designated by reference numerals 24A and 30A which comprise the drill guides. This reference is believed to be of only general interest concerning the present invention in that the drill guide is integrally formed with the clamp and is thus not moveable with respect thereto.
U.S. Pat. No. 4,256,420 to Day discloses a nail head drilling guide including a handle attached to a plate through a body portion having holes 30 therein for guiding the nails. There is not believed to be any disclosure or suggestion in this patent of the attachment of the inventive guide to a jaw of a saw guide.
U.S. Pat. No. 4,421,112 to Mains, et al. discloses a tibial osteotomy guide assembly and method including a device attachable to the tibia through elongated pins and having a device 20 with bores therein which are provided so as to guide the insertion of pins into the tibia which are utilized to guide the movements of a saw. This device is believed to be of only general interest concerning the present invention in that there is no ability of the guide to be adjustable with respect to a clamping device.
U.S. Pat. No. 4,444,180 to Schneider, et al. discloses a clamp-like device wherein one of the jaws thereof comprises a drill guide. This device is believed to be of only general interest concerning the present invention since the drill guide thereof is not adjustable with respect to the jaw on which is it integrally formed.
The following prior art is believed to be generally related to the inventive patella clamp:
U.S. Pat. Nos. 339,526 to Butterworth, 2,570,048 to Cooke, et al. and 4,147,168 to Hayes, et al. all relate to tools for placing some sort of identifying mark on an animal such as a ring through the nose or an identification tag. Hayes, et al. is believed to be slightly more relevant that Butterworth or Cooke, et al. in that Hayes, et al. discloses a plunger 54 constrained to move linerally by the opening 58 formed in an elongated housing portion 60 thereof.